After making this post, I came across the post "Slow Printing or Print Errors due to Microsoft Windows Update KB4560960 for June". This seemed to describe the problem I was experiencing. It blamed updates KB4560960 and KB4557957. I found that the laptop in question had had update KB4557957 but not KB4560960. So, I uninstalled KB4557957, rebooted and tried to print again. Unfortuately, it didn't work. I still can't print from that laptop. So, I'm still at a loss and would welcome suggestions.
I've just upgraded my broadband from BT fibre to a box to Virgin Media fibre to the house. I've set up several laptops and a desktop. I can print from all these machines, except one. My wife's HP Pavilion can't print whether it is connected by wi-fi or ethernet. The job goes to the print queue, starts to show printing and then shows error and does not print. I've had to save her jobs to pdf and then print them from another laptop or desktop. It can connect to the new modem and either directly or via a Coredy repeater, but just not print. I've run out of ideas. Any suggestions?